This invention is generally concerned with web processing apparatus and more particularly with apparatus for processing elongate portions of a web of coded sheet.
As shown in U.S. Pat. No. 4,593,893 for a Method And Apparatus for Sequentially Advancing And Cutting Forms From Two Continuous Web Forms, issued June 10, 1986 to Walter Suter, apparatus has been provided for processing overlapped portions of a web of coded sheets, wherein each of the web portions includes a single marginal edge having sprocket holes formed therein, utilizing tractor structure which engages the sprocket holes of the marginal edge of each web portion for independently advancing the web portions on a table to cutting structure, cutting the web portions, and sorting the sheets cut from the web in accordance with the codes marked thereon.
Thus it is known in the art to provide tractor structures for independently feeding separated portions of a web of coded sheets downstream in overlapped paths of travel to cutting structure, cutting the sheets from the web and sorting the cut sheets in accordance with their codes. However, it has been found that rapidly accelerating and decelerating a web portion solely by means of tractor structure which engages only one marginal edge, results in the tractor structure having a tendency to tear the sprocket holes. Moreover, when the marginal edge is defined by a perforate line formed in the web portion, the tractor structure tends to separate the marginal edge from the web portion.
Accordingly:
An object of the invention is to provide improved web processing apparatus;
Another object is to utilize tractor structures for aligning separated web portions of a web of sheets;
Another object is to provide improved apparatus for processing a web of coded sheets, including structure for feeding separated portions of the length of the web in engagement with tractor structure for guiding the web portions in separate paths of travel; and
Yet another object is to provide apparatus for feeding an elongate portion of a web of sheets downstream in a path of travel from guiding means, against the upstream force exerted by the guiding means.